/*
 * 'tty.h' defines some structures used by tty_io.c and some defines.
 *
 * NOTE! Don't touch this without checking that nothing in rs_io.s or
 * con_io.s breaks. Some constants are hardwired into the system (mainly
 * offsets into 'tty_queue'
 */

#ifndef _TTY_H
#define _TTY_H

#include <termios.h>

#define TTY_BUF_SIZE 1024

struct tty_queue {
    unsigned long data;
    unsigned long head;
    unsigned long tail;
    struct task_struct *proc_list;
    char buf[TTY_BUF_SIZE];
};

#define INC(a)   ((a) = ((a) + 1) & (TTY_BUF_SIZE - 1))
#define DEC(a)   ((a) = ((a)-1) & (TTY_BUF_SIZE - 1))
#define EMPTY(a) ((a).head == (a).tail)
#define LEFT(a)  (((a).tail - (a).head - 1) & (TTY_BUF_SIZE - 1))
#define LAST(a)  ((a).buf[(TTY_BUF_SIZE - 1) & ((a).head - 1)])
#define FULL(a)  (!LEFT(a))
#define CHARS(a) (((a).head - (a).tail) & (TTY_BUF_SIZE - 1))
#define GETCH(queue, c) \
    (void)({c=(queue).buf[(queue).tail];INC((queue).tail); })
#define PUTCH(c, queue) \
    (void)({(queue).buf[(queue).head]=(c);INC((queue).head); })

#define INTR_CHAR(tty)    ((tty)->termios.c_cc[VINTR])
#define QUIT_CHAR(tty)    ((tty)->termios.c_cc[VQUIT])
#define ERASE_CHAR(tty)   ((tty)->termios.c_cc[VERASE])
#define KILL_CHAR(tty)    ((tty)->termios.c_cc[VKILL])
#define EOF_CHAR(tty)     ((tty)->termios.c_cc[VEOF])
#define START_CHAR(tty)   ((tty)->termios.c_cc[VSTART])
#define STOP_CHAR(tty)    ((tty)->termios.c_cc[VSTOP])
#define SUSPEND_CHAR(tty) ((tty)->termios.c_cc[VSUSP])

struct tty_struct {
    struct termios termios;
    int pgrp;
    int stopped;
    void (*write)(struct tty_struct *tty);
    struct tty_queue read_q;
    struct tty_queue write_q;
    struct tty_queue secondary;
};

extern struct tty_struct tty_table[];

/*	intr=^C		quit=^|		erase=del	kill=^U
    eof=^D		vtime=\0	vmin=\1		sxtc=\0
    start=^Q	stop=^S		susp=^Z		eol=\0
    reprint=^R	discard=^U	werase=^W	lnext=^V
    eol2=\0
*/
#define INIT_C_CC "\003\034\177\025\004\0\1\0\021\023\032\0\022\017\027\026\0"

void rs_init(void);
void con_init(void);
void tty_init(void);

int tty_read(unsigned c, char *buf, int n);
int tty_write(unsigned c, char *buf, int n);

void rs_write(struct tty_struct *tty);
void con_write(struct tty_struct *tty);

void copy_to_cooked(struct tty_struct *tty);

#endif
